Cam operated circuit breaker with single stroke manual spring charging means

ABSTRACT

A circuit breaker comprises improved means for manually operating the breaker from the open position to the closed position. The circuit breaker comprises a spring-closing mechanism, and interlock means is provided to prevent operation of the spring-closing mechanism when the contacts are in the closed position.

United States Patent Richard Hauser Pittsburgh, Pa.

Oct. 24, 1968 Mar. 9, 1971 Westinghouse Electric Corporation Pittsburgh, Pa.

Inventor App]. No. Filed Patented Assignee CAM OPERATED CIRCUIT BREAKER WITH SINGLE STROKE MANUAL SPRING CHARGING MEANS 10 Claims, 8 Drawing Figs.

US. Cl. 200/153, 185/37 Int. Cl I-IOIh 3/30, H0 1 h 3/42 Field of Search 335/190,

73, 24;200/153.7,153.8,153.11, 74,153,153.13, 146(Curs0ry),50.15,144, 153.22; 185/37 [56] References Cited UNITED STATES PATENTS 2,914,635 11/1959 Lester et a1. 200/50.15x 2,943,163 6/1960 200/l53(.8)x 3,095,489 6/1963 200/153 3,171,938 3/1965 200/153 3,207,879 9/1965 Goodwin. ZOO/153.7

Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorneys-A. T. Stratton, C. L. Mc Hale and W. A. Elchik ABSTRACT: A circuit breaker comprises improved means for manually operating the breaker from the open position to the closed position. The circuit breaker comprises a spring-closing mechanism, and interlock means is provided to prevent operation of the spring-closing mechanism when the contacts are in the closed position.

PATENTED MAR 9 :97:

SHEET 1 BF 5 INVENTOR Richard Houser ATTORNEY WITNESSES PATENTED MAR 9197! SHEET 2 BF PATENTEDMAR 9i97| 3,569,652

SHEET u BF 5 CAM OPERATED CIRCUIT BREAKER WITH SINGLE STROKE MANUAL SPRING CHARGING MEANS CROSS REFERENCE TO RELATED APPLICATIONS Certain features that are herein disclosed are disclosed and claimed in the following applications which are filed concurrently herewith: Fred Bould et al., Ser. No. 770,296; Edmund Kuhn, Ser. No. 770,305; Fred Bould, Ser. No. 770,297; Fred Bould, Ser. No. 770,l49; and Nagar Patel, Ser. No. 770,236.

BACKGROUND AND OBJECTS OF THE INVENTION For certain applications in the circuit breaker art, it is desirable to provide a spring-closing mechanism that can be operated from a spring-discharged position without requiring that the operator crank the operating handle a plurality of times. Thus, an object of this invention is to provide a springoperated circuit breaker comprising a crank shaft that is rotatable from a spring-discharged position through an angle of more than 180 to a spring-charged operating position, and manual operating means that is rotatable'through an angle of less then 180 to operate the crank shaft from the springdischarged position to the spring-charged operating position. Another object of this invention is to provide an improved circuit breaker with a manual operating means operable in a single stroke to charge closing spring means to release the charged closing spring means to effect a closing operation of the circuit breaker, Another object of this invention is to provide a circuit breaker comprising a spring-closing mechanism and manual operating means for operating the spring-closing mechanism from an open position to a closed position with in terlock means preventing a closing operation of the springclosing mechanism when the circuit breaker contacts are in the closed position.

SUMMARY OF THE INVENTION A circuit breaker comprises a crank shaft rotatable in an operating direction from a spring-discharged position through an angle of more than 180 to a spring-charged operating position, and manual operating means rotatable through an angle of less than 180 to move the crank shaft from the springdischarged position to the spring-charged operating position. A rotation of the manual operating means through an angle of 97 will rotate the crank shaft through an angle of more than 187 to thereby position the crank shaft in the spring-charged operating position. The manual operating means comprises a manually operable member supported for movement about a fixed pivot and a pull-member pivotally supported on the manually operable member to cooperate with a crank on the crank shaft to pull the crank shaft from the spring-discharged position to the spring-charged operating position upon pivotal movement of the manually operable member. The circuit breaker does not comprise latch means for latching the spring charged mechanism in the spring-charged operating position so that when the crank shaft reaches the spring-charged operating position the closing springs will automatically take over to rotate the crank shaft in the operating direction to the spring-discharged position. A cam-operated closing means comprises a closing cam that is fixed to the crank shaft and that operates against a closing linkage to cam the movable contact to the closed position upon rotation of the crank shaft from the spring-charged operating position to the springdischarged position. The circuit breaker comprises interlock means operable automatically to prevent an operation of the spring-closing mechanism, by operation of the manual operating means, when the circuit breaker contracts are in the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end view, with parts broken away and with certain parts left out for the purpose of clarity, of a circuit breaker constructed in accordance with principles of this invention;

in the initial position when the circuit breaker is in the open position;

FIG. 6 is a view similar to FIG. 5 illustrating the position of the handle-operating means when the handle-operating means has been manually operated to move the crank shaft from the spring-discharged position in FIG. 5 to the spring-charged operating position seen in FIG. 6;

FIG. 7 is a view similar to FIGS. 5 and 6 illustrating the position of parts reached after the circuit breaker has been operated to the closed position and while the handle-operating means is being moved back to the initial position; and

FIG. 8 is a view similar to FIGS..5--7 illustrating the position of parts when the circuit breaker is in the closed position and the handle-operating means has been returned to the initial position.

DESCRIPTION THE PREFERRED EMBODIMENT Referring to the drawings, there is shown in FIG. 1 and 2 a three-pole circuit breaker 5 comprising a housing structure 7 and a circuit breaker structure 9 supported on the housing structure 7.

The housing structure 7 comprises a metallic base plate 11, a pair of spaced metallic sideplates 13 secured to flanges of the base plate 11, a pair of spaced metallic center plates 17 secured to the base plate 11, and a back wall structure indicated generally at 19. I

The circuit breaker structure 9-is a three-pole structure comprising a stationary contact 21 and a movable contact 23 for each pole unit. The stationary and movable contact struc tures 21, 23 along with the supports thereof, are more specifcally described in the copending application of Fred Bould, Ser. No. 770,149 and of Fred Bould et al., Ser. No. 770,297. Each of the movable contacts 23 is supported on a conducting contact arm 25 that is pivotally supported on a terminal conductor27 by means of supportmeans 29. In each pole unit, a separate insulating connecting member 31 is pivotally connected at one end thereof to the contact arm 25 and at the other end thereof to a lever 33that is welded to a common jackshaft 35. As can be seen in FIG. 1, the jackshaft 35 extend across all of the poles of the circuit breaker, and there is a separate lever 33 for each pole unit welded to the jackshaft 35. Only one of the contact structures is shown in FIG. 1. The contact structures for the center pole unit and for the lefthand (FIG. 1) pole unit are left off of the drawing in FIG. 1 merely for the purpose of clarity. It can be understood that the contact structures for all three pole units are the same as the one contact structure shown in FIGS. 1 and 2.

The jackshaft 35 is supported on the sideplates 13 and center plates 17 for pivotal movement about the elongated axis thereof in a manner more specifically described in the above-mentioned application of Fred Bould et al. Ser. No. 770,295. The connecting members 31, levers 33 and jackshaft 35 are part of a spring-closing mechanism 39 that is operable to close the contacts 21, 23.

The spring-closing mechanism 39 comprises a link member 41 that is pivotally connected, at one end thereof, to the lever 33 of the center pole unit by means of a pin 43. The link 41 is pivotally connected at the other end thereof to a link 45 by means of a pin 47. A roller member 49 is mounted on the pin 47 to cooperate with a closing cam 51. The link 45 is pivotally connected at the other end thereof to a latch member 53 by means of a pin 55. The latch member 53 is mounted for pivotal movement on a fixed pivot 57 that is supported on the center plate 17 that is seen on the left in FIG. 1. As can be understood with reference to FIGS. 1 and 2, the links 45 and 53 are positioned on the left-hand side of the left center plate 17 (FIG. 1). A tension spring 59 is supported at one end thereof on a stationary pin 61 and operatively connected to the pin 55 at the other end thereof in order to reset the linkage in a manner to be hereinafter described. The latch member 53 engages a trip shaft 63 that is a rod with a cutout portion 65 near where the latch 53 engages the periphery of the trip shaft 63. The cutout portion 65 is provided so that when the trip shaft 63 is rotated in a counterclockwise direction from the FIG. 2 position to the FIG. 3 position the latch member 53 will be free to pivot to the open position seen in FIG. 3. The trip shaft 63 is supported on one of the sideplates l3 and one center plate 17 for pivotal movement about the elongated axis thereof. The links 53, 45, 47 and trip shaft 63, along with the operation of these members are more specifically described in the above mentioned application of Fred Bould et al. Ser. No. 770,296.

The closing cam 51 is fixedly secured to a crank shaft 73 that is rotatably mounted on suitable bearing means that are supported on the center plates 17. The crank shaft 73 is mounted for rotational movement about the elongated axis thereof. A pair of crank arms 75 are fixedly supported on the crank shaft 73 at the opposite ends of the crank shaft 73. A separate tension spring 77 is supported at one end thereof on a support 79 that is pivotally connected to the associated crank arm 75 by means of a pin 81. Each of the tension springs 77 is connected at the other end thereof, to a pin 83 that is supported on the center plates 17.

A handle-operating mechanism indicated generally at 87 (FIGS. 1 and 8) is provided for manually closing the circuit breaker. As shown in FIGS. 58, a crank 89, having a notch or catch means 91 therein, is fixedly secured to the crank shaft 73. A generally U-shaped supporting plate 93 is fixedly secured, at the right portion thereof, to the base plate 11. A generally U-shaped manually operable member 95 is pivotally mounted on a pin 97, that is. supported on and between the legs of the U-shaped supporting member 93. A torsion spring 99 is coiled around the pin 97, and engages a stationary pin 101, that is supported onthe support 93, and a pin 103, that is supported on the member 95, to bias the manually operably member 95 in a clockwise (FIG. 5) direction to the initial position shown in FIG. 5. The U-shaped manually operable member 95 is provided with an extension 105 that receives an elongated handle rod 107. A generally U- shaped hook member or pull member 109 is pivotally supported on and between the legs of the member 95 by means of a pin 111. The hook member 109 is biased in a clockwise (FIG. 5) direction by means ofa torsion spring 113. A pin 1 is supported on and between the legs of the hook member 109 to engage the crank 89 in the notch or catch means 91 during operation of the manual operating means 87. An interlock member 119 is fixedly secured to the member 109 to cooperate with the pin 47 in order to prevent cooperative engagement between the members 109 and 89 when the contacts are in the closed position.

The circuit breaker is shown in FIG..2 in the closed position. The cam member 51 comprises a cam surface that cooperates with the roller 49 and that can be more specifically described as having three continuous surface portions that cooperate with the roller 49. As seen in FIG. 2, a'fixed-radius surface portion 125 engages the roller 49. The cam surface is shaped to provide a reset surface portion 127 and a closing surface portion 129. Referring to FIG. 2, the fixed-radius surface portion 125 of the cam 51 engages the roller 49 to position the link 41 in the closed position with the link 41 operating through the lever 33 of the center pole unit to maintain the jackshaft 35 in the closed position thereby to maintain the three contact arms of the three pole units in the closed position illustrated in FIG. 2. The link 41 will maintain the contact 25 in the closed position only so long as the link 41 is held in the closed position through the link 45 by means of the latch 53 that is latched in the reset position shown in FIG. 2 by means of a trip shaft 63.

The trip shaft 63 can be manually pivoted to the open position by manual operation of a trip lever 131 (FIG. 1) or automatically operated to the open position by operation of an electromagnetic trip device indicated generally at 133 in FIG. 1, The trip device i 133 is more specifically described in the above-mentioned copending application of Nagar Patel Ser. No. 770,236. The trip device 133 is automatically operated in response to an abnormal or overload current condition above a predetermined value to rotate the trip bar 63 to the open position.

With the circuit breaker in the closed position seen in FIG. 2, the breaker is opened, either automatically or manually, by counterclockwise (FIG. 2) rotation of the trip shaft 63 from the latching position seen in FIG. 2 to the open position seen in FIG. 3. Upon movement of the trip shaft 63 to the open position, the trip shaft 63 is moved to permit the latch member 53 to move in the notch 65 thereby permitting counterclockwise movement of the latch 53 about the fixed pivot 57 to thereby permit movement of the link 45 and link 41 to the collapsed position seen in FIG. 3. Thus, upon movement of the trip shaft 63 to the open position, an opening spring 134, aided by backup springs (not shown) behind the stationary contact structure, serve to bias the jackshaft 35 in a clockwise (FIG. 2) direction to move the three contact arms 25 to the open position. As can be seen in FIG. 3, the links 41, 45 collapse with the pivot 47 and roller 49 moving downward to the position seen in FIG. 3 during a tripping or opening operation.

With the circuit breaker in the open position seen in FIG. 3, the circuit breaker is closed by operation of the manual operating means 87 illustrated in FIGS. 58. The manual operating means 87 is shown in the initial position in FIG. 5 with the circuit breaker in the open position as indicated from the links 45, 41 (FIG. 2) to cooperate with the interlock member 119 in a manner to be hereinafter specifically described. When it is desired to close the circuit breaker, the operating handle rod 107 is operated to pivot the manually operable member in a counterclockwise (FIG. 5) direction. As can be seen in FIG. 6 the pull member 109 has a surface 135 that rests on a spacer 137 (that is positioned on the crank shaft 73) to limit clockwise movement of the pull member 109 about the pivot 111 when the member 95 is in the initial position seen in FIG. 5. The undersurface of the pull member 95 is formed with a depression at 136 (seen in FIG. 6) adjacent the surface 135. During the first approximately 8 of angular movement of the member 95 from the initial position seen in FIG. 5, the depression 136 will move against the spacer 137 permitting the pull member 109 to move clockwise on the pivot 11, under the bias of the spring 113, during which movement the pin will move into the captured position in the notch 91 of the crank 89, and upon further angular movement of the member 95 the pin 115 will pull the crank 89 in a counterclockwise direction. The relatively unrestrained first 8 of angular travel of the member 95 permits the operator to easily get the handle rod 107 in a free position away from the front of the breaker before the operator must work to charge the springs 77. The geometry, construction and support of the members 95, 109, 89 are such that a total movement of 97 of the member 95 about the pivot 97 will rotate the crank shaft 73 187 from the spring-discharged position seen in FIG. 5 to the spring-charged operating position seen in FIG. 6.

During movement of the crank shaft 73 from the springdischarged position seen in FIG. 5 to the spring-charged operating position seen in FIG. 6, the cam member 51 is operated from the position seen in FIG. 3 through and past the position seen in FIG. 4. As will be understood with reference to FIGS. 3 and 4, as the crank shaft 73 moves counterclockwise the fixed-radius surface moves past the roller 49, and as the reset surface 127 moves adjacent the roller 49 the roller 49 is free to move to the left and upward permitting the link 45 to move to the reset position and permitting the latch member 53 to be move clockwise about the pivot 57 from the tripped or open position seen in FIG. 3 to the reset position seen in FIG. 4 under the bias of the resetting spring 59. When the latch member 53 is'moved to the reset position seen in FIG. 4, spring means (not shown) operate automatically to bias the trip shaft in a clockwise direction to the reset position seen in FIG. 4 wherein the periphery of the trip shaft 63 latches the latch member 53 against counterclockwise movement to hereby latch the circuit breaker linkage in the reset position seen in FIG. 4. Thus, as the crank shaft 73 is manually operated in a counterclockwise direction the reset spring 59 operates to reset the linkage as the reset surface 127 of the cam 51 passes the roller 49. Continued counterclockwise movement of the crank shaft 73 past the reset position seen in FIG. 4 to the spring-charging operating position seen in FIG. 6 will move the closing cam surface 129 of the cam 51 adjacent the roller 49, and the crank arms 75 will be moved to position the spring support pins 81 over center (the crank arms 75 will be moved through an angle of more than 180 from the spring-discharged position seen in FIG. 3) such that the closing springs 77 will operate to bias the crank shaft 73 in a counterclockwise direction toward the closed portion seen in FIG. 2. As shown in FIG. 6, the manually operable member 95 has been moved counterclockwisethrough an angle of 97 to rotate the crank shaft 73 through an angle of 187. At some point of rotation after the crank shaft has rotated through an angle of more than 180 and before the crank shaft has rotated through an angle of about 187, depending for example on the friction of parts of the breaker and the length of the moment arm from the axis of the crank shaft to the axis of the spring supporting pins 81, the closing springs 77 will take over to rapidly rotate the crank shaft 73 counterclockwise to the spring-discharged contact-closed position seen in FIG. 2. As was previously set forth, at the time that the crank shaft has moved sufficiently to provide that the closing springs 77 will take over and discharge, the cam member 51 has been moved to a position such that the closing cam surface 129 is adjacent the 'roller 49 so that upon movement of the crank shaft 73 from the spring-charged operating position (FIG. 6) to the spring-discharged position seen in FIG. 2 the closing cam surface 129 will move against the roller 49 to thrust the roller 49 and linkage 45, 41 to the contact-closed position as seen in FIG. 2. As can be understood with reference to FIG. 2, closing movement of the link 41 will operate through the lever 33 of the center pole unit to move the jackshaft 35 counterclockwise, and since the three levers 33 for the three pole units, are all connected to the jackshaft 35, this movement will simultaneously operate through the three levers 31 to pivot the three contact arms to the contact-closed position seen in FIG. 2. Near the end of the closing movement of the cam member 51, it will be understood the closing cam surface 129 moves past the roller 49 and the fixed-radius surface 125 moves against the roller 49. Movement of the fixed-radius cam surface 125 against the toll roller 49 will not affect the closed position of the contacts since the fixed-radius surface 125 serves to prop the roller 49 without affecting the position of the contact arms. Thus, operation of the handle-operating mechanism 87 from the initial position seen in FIG. 5, wherein the circuit breaker is in the tripped or open position as indicated by the pin 47, to the spring-charged operating position seen in FIG. 6 operates the crank shaft 73 to move the crank arms 75 over center past the 180 angle of travel of the crank shaft 73 to the spring-charged operating position (FIG. 6) wherein the closing springs 77 operates to bias the crank shaft 73 counterclockwise toward the springdischarged position seen in FIG. 2. During the movement of the crank shaft 73 from the spring-discharged position (FIG. 2) to the spring-charged operating position (FIG. 6), the cam member 51 is moved to move the reset cam surface 127 past the roller 49 whereupon the spring 59 serves to reset the links 41, 45 and latch 53 (FIG. 4), and continued movement of the crank shaft 73 to the spring-charged operating position (FIG. 6) will move the closing cam surface 129 adjacent the roller 49 so that when the closing springs 77 take over to complete the 360 travel of the crank shaft 73 the closing cam surface 129 will move against the roller 49 to thrust the contact arms 25 to the contact-closed position seen in FIG. 2.

With the cam member 51 comprising the surfaces'1'25, 127, 129, it can be understood that if the contacts are in the closed position seen in FIG. 2 it would be desirable to prevent an operation of the crank shaft 73 through the 360 of travel from the spring-discharged contact-closed position (FIG. 2) back to the spring-discharged contact-closed position (FIG. 2) since such an operation would merely reclose the contacts and because the contacts would open and close during such an operation. Thus, interlock means is provided to automatically prevent operating engagement between the hook member 109 and crank 89 when the contacts are in the closed position. A rigid interlock member 119 (FIGS. 1 and 5-8) is fixedly secured to the side of thehook member 109. The knee picot pin 47 between the toggle links 45, 41 is extended over the to where the pin 47 is in the path of movement of the interlock member 119 when the contacts are in the closed position. With the pin 47 in the contact-closed position seen in FIGS. 2 and 8, the interlock member 119 will rest on the pin 47 to prevent clockwise movement of the hook member 109 about the pivot 111 to thereby prevent engagement of the pin 115 in the notch 91 of the crank 89. Thus, followinga closing operation of the circuit breaker, the handle 107 is released and the spring 99 biases the manually operable member 95 in a clockwise directionwhereupon the interlock member 119 engages the pin 47 (FIG. 7), and as the member 95 reaches the initial position seen in FIG. 8 the hook member 109 maintained in the inoperative position seen in FIG. 8. With the hook member 109 maintained in the inoperative position as seen in FIG. 8,a crank of the handle-operating means 87 will be ineffective to operate the crank shaft 73. As can be understood with reference to FIGS. 3 and 5, when the circuit breaker is in the tripped or open position the pin 47 is dropped to the tripped or open position seen in FIGS. 3 and 5 to thereby permit clockwise movement of. the hook member 109 to the position seen in FIG. 5, and with the hook member 109 in the position seen in FIG. 5, a manual operation of the manually operable member 95 will serve to operate the crank shaft 73 to thereby close the contacts in the same manner as was hereinbefore described.

From the foregoing, it can be understood that there is provided by this invention an improved circuit breaker comprising a crank shaft operable through an angle of more than l80 (187 in one embodiment) from a spring-discharged position to a spring-charged operating position, and manual operating means operable through an angle ofless than (97 in the one embodiment) to operate the crank shaft from the springdischarged position to the spring-discharged operating position. The manual operating means comprises a manually operable member supported for movement about a fixed pivot and a hook member pivotally supported on the manually operable member to cooperate with a crank on the crank shaft to pull the crank shaft from the spring-discharged position to the spring-charged operating position upon manual operation of the manually operable member. The circuit breaker is a single-stroke circuit breaker in that when the crank shaft reaches the spring-charged operating position a pair of closing springs, that are connected to the crank shaft, are moved over center such that the closing springs will take over and rotate the crank shaft to the contact-closed position as the closing springs discharge. A cam member, that is fixedly secured to the crank shaft, cooperates with a roller, that is connected to the knee pivot pin of the pair of operating links, to thrust the movable contact arms to the closed position when the links are latched in a reset position by latch means. The circuit breaker is opened, either manually or automatically, by operation of a trip shaft that releases the latch member to thereby release the operating links permitting the links to collapse to a tripped or open position. With the circuit breaker in the open position, the circuit breaker is closed by a single stroke of the handle-operating means during which movement the cam member moves first to position a reset cam surface adjacent the roller permitting the roller to move to a reset position under the bias of the reset spring which serves to operate the latch member and links to a reset position. Continued movement of the cam member, under the control of the singlestroke movement of the manual operating means, moves the cam member such that a closing cam surface moves adjacent the roller after the linkages have been reset. With the closing cam surface adjacent the roller, the crank shaft will move to an overcenter position where the closing springs bias the crank shaft toward the contact-closed spring-discharged position, and the closing springs will take over moving the crank shaft to the contact-closed spring-discharged position during which movement the closing cam surface will move against the roller to operate through the latched linkages to thrust the roller to operate through the latched linkages to thrust the movable contact arms to the contact-closed position. The cam surface comprises a fixed-radius cam surface so that once the contacts reach the closed position the fixed-radius cam surface will serve to prop the roller, and movement of the cam while the roller engages the fixed-radius cam surface will not affect the closed position of the contacts. The circuit breaker comprises improved interlock means comprising an interlock member of the hook member that cooperates with the knee pivot pin of the toggle links to engage the interlock member and prevent cooperative engagement between the hook member and crank when the contacts are in the closed position to thereby prevent an operation of the crank shaft when the circuit breaker is in the contact-closed spring-discharged position.

lclaim:

1. A circuit breaker comprising a pair of contacts, a spring closing mechanism for closing said contacts, said spring closing mechanism comprising a crank shaft, closing spring means connected to said crank shaft, said crank shaft being rotatable about a fixed pivot in an operating direction through an angle of more than 180 from a spring-discharged position to a spring-charged operating position to charge said closing spring means and to position said crank shaft and said charged closing spring means overcenter such that said charged closing spring means biases said crank shaft in said operating direction toward said spring-discharged position, said charged closing spring means being dischargeable to rotate said crank shaft in said operating direction from said spring-charged operating position to said spring-discharged position, means operated by said crank shaft to close said contacts upon rotation of said crank shaft from said spring-charged operating position to said spring-discharged position, manual operating means comprising a manually operable member supported for movement about a fixed pivot through an angle of less than 180 from an initial position to an operating position, a pull member movably supported on said manually operable member, catch means on said crank shaft cooperating with said pull member, and upon a single-stroke manual operation of said manually operable member from said initial position to said operating position said pull member cooperating with said catch means to operate said crank shaft from said springdischarged position to said spring-charged operating position.

2. A circuit breaker according to claim 1, and said pull member being pivotally supported on said manually operable member.

3. A circuit breaker according to claim 2, a first spring means biasing said manually operable member in a first direction to said initial position, and a second spring means biasing said pull member on said manually operable member in said first direction to bias said pull member into cooperative engagement with said catch means.

4. A circuit breaker according to claim 1, said crank shaft being rotatable through an angle of between 180 and 200 from said spring-discharged position to said spring-charged operating position, and said manually operable member being pivotable through an angle of between 80 and 100 to operate said crankshaft from said spring-discharged position to said spring-charged operating position.

5. A circuit breaker according to claim 1, and upon operation of said crank shaft to said spring-charged operating position said closing spring means automatically operating to move said crank shaft in said operating direction to said spring-discharged position to effect a closing operation of said contacts.

5. A circuit breaker comprising a stationary contact, a movable contact, a movable contact arm carrying said movable contact and movable to open and close said contacts, an operating linkage, releasable latch means latching said operating linkage in a reset position, means for releasing said latch means, opening spring means, upon release of said latch means with said contacts in the closed position said operating linkage moving to a collapsed position and said opening spring means operating to move said movable contact arms to the open position, a spring-closing mechanism for moving said movable contact arm to the closed position, said spring-closing mechanism comprising a crank shaft, closing spring means connected to said crank shaft, said crank shaft being rotatable about a fixed pivot in an operating direction through an angle of more than from a spring-discharged position to a spring-charged operating position to charge said closing spring means and to position said crankshaft and said charged closing spring means and to position said crank shaft and said charged closing means overcenter such that said charged closing spring means biases said crank shaft in said operating direction toward said spring-discharged position, said charged closing-spring means being discha'rgeable to rotate said crank shaft in said operating direction from said spring-charged operating position to said spring-discharged position, cam means operated by said crank shaft to affect resetting and relatching of said collapsed linkage during movement of said crank shaft from said spring-discharged position to said spring-charged operating position, and upon rotation of said crank shaft from said spring-charged operating position to said spring-discharged position, said cam means operating through said reset linkage to move said movable contact arms to the closed position, manual operating means comprising a manually operable member supported for movement about a fixed pivot through an angle of less than 180 from an initial position to an operating position, a pull member movably supported on said manually operable member, catch means on said crank shaft cooperating with said pull member, and upon a single-stroke manual operation of said manually operable member from said initial position to said operating position said pull member cooperating with said catch means to operate said crank shaft from said spring-discharged position to said spring-charged operating position.

7. A circuit breaker according to claim 6, said cam means comprising a cam follower operatively connected to said operating linkage and a cam member fixedly connected to said crank shaft, said cam membercomprising a reset surface a fixed radius surface and a closing surface, during said manual closing operation of said circuit breaker said cam member 7 moving in one direction to move said reset surface against said cam follower to effect a resetting operation of said circuit breaker and then to move said closing surface against said cam follower to thrust said cam followerto the closed position to move said movable contact arm to the closed position and said cam member then moving to move said fixed radius surface against said cam follower during which movement of said fixed radius surface against said cam follower said fixed radius surface serves to prop said cam follower such that movement of said cam member while said fixed radius surface is adjacent said cam follower will not affect the closed position of said movable contact arm.

8. A circuit breaker according to claim 1, said circuit breaker comprising a linkage and latch means latching said linage in a. reset position when said contacts are closed and said crank shaft is in said spring-discharged position, and said circuit breaker comprising interlock means automatically operable to prevent cooperative engagement between said pull member and said catch means when said linkage is in said reset position and said circuit breaker is in the springdischarged contact-closed position.

9. A circuit breaker according to claim 6, said cam means comprising a cam follower connected to said linkage and a cam member connected to said crank shaft, upon operation of said manually operable member from said initial position to said operating position said pull member operating when said contact arm is in the open position and said linkage is in the collapsed position to cooperate with said catch means to rotate said crank shaft from said spring-discharged position to said spring-charged operating position during which movement of said cam member operates said cam follower to effect a resetting operation of said linkage and a relatching of said reset linkage prior to movement'ofsaid crank shaft overcenter and during which further movement of said crank shaft said crank shaft moves overcenter to said spring-charged operating position whereupon said closing spring means takes over to move said crank shaft in said operating direction from said spring-charged operating position to said spring-discharged position during which movement of said cam member operates through said cam follower and said reset latched linkage to move said movable contact arm to the closed position, and interlock means operating automatically to prevent cooperative engagement between said pull member and said catch means when said contact arm is in said closed position.

10. A circuit breaker according to claim 9, and said interlock means comprising a first interlock member connected to said pull member and a second interlock member connected to said linkage. 

1. A circuit breaker comprising a pair of contacts, a spring closing mechanism for closing said contacts, said spring closing mechanism comprising a crank shaft, closing spring means connected to said crank shaft, said crank shaft being rotatable about a fixed pivot in an operating direction through an angle of more than 180* from a spring-discharged position to a springcharged operating position to charge said closing spring means and to position said crank shaft and said charged closing spring means overcenter such that said charged closing spring means biases said crank shaft in said operating direction toward said spring-discharged position, said charged closing spring means being dischargeable to rotate said crank shaft in said operating direction from said spring-charged operating position to said spring-discharged position, means operated by said crank shaft to close said contacts upon rotation of said crank shaft from said spring-charged operating position to said spring-discharged position, manual operating means comprising a manually operable member supported for movement about a fixed pivot through an angle of less than 180* from an initial position to an operating position, a pull member movably supported on said manually operable member, catch means on said crank shaft cooperating with said pull member, and upon a single-stroke manual operation of said manually operable member from said initial position to said operating position said pull member cooperating with said catch means to operate said crank shaft from said spring-discharged position to said spring-charged operating position.
 2. A circuit breaker according to claim 1, and said pull member being pivotally supported on said manually operable member.
 3. A circuit breaker according to claim 2, a first spring means biasing said manually operable member in a first direction to said initial position, and a second spring means biasing said pull member on said manually operable member in said first direction to bias said pull member into cooperative engagement with said catch means.
 4. A circuit breaker according to claim 1, said crank shaft being rotatable through an angle of between 180* and 200* from said spring-discharged position to said spring-charged operating position, and said manually operable member being pivotable through an angle of between 80* and 100* to operate said crankshaft from said spring-discharged position to said spring-charged operating position.
 5. A circuit breaker according to claim 1, and upon operation of said crank shaft to said spring-charged operating position said closing spring means automatically operating to move said crank shaft in said operating direction to said spring-discharged position to effect a closing operation of said contacts.
 5. A circuit breaker comprising a stationary contact, a movable contact, a movable contact arm carrying said movable contact and movable to open and close said contacts, an operating linkage, releasable latch means latching said operating linkage in a reset position, means for releasing said latch means, opening spring means, upon release of said latch means with said contacts in the closed position said operating linkage moving to a collapsed position and said opening spring means operating to move said movable contact arms to the open position, a spring-closing mechanism for moving said movable contact arm to the closed position, said spring-closing mechanism comprising a crank shaft, closing spring means connected to said crank shaft, said crank shaft being rotatable about a fixed pivot in an operating direction through an angle of more than 180* from a spring-discharged position to a spring-charged operating position to charge said closing spring means and to position said crank shaft and said charged closing spring means and to position said crank shaft and said charged closing means overcenter such that said charged closing spring means biases said crank shaft in said operating direction toward said spring-discharged position, said charged closing-spring means being dischargeable to rotate said crank shaft in said operating direction from said spring-charged operating position to said spring-discharged position, cam means operated by said crank shaft to affect resetting and relatching of said collapsed linkage during movement of said crank shaft from said spring-discharged position to said spring-charged operating position, and upon rotation of said crank shaft from said spring-charged operating position to said spring-discharged position, said cam means operating through said reset linkage to move said movable contact arms to the closed position, manual operating means comprising a manually operable member supported for movement about a fixed pivot through an angle of less than 180* from an initial position to an operating position, a pull member movably supported on said manually operable member, catch means on said crank shaft cooperating with said pull member, and upon a single-stroke manual operation of said manually operable member from said initial position to said operating position said pull member cooperating with said catch means to operate said crank shaft from said spring-discharged position to said spring-charged operating position.
 7. A circuit breaker according to claim 6, said cam means comprising a cam follower operatively connected to said operating linkage and a cam member fixedly connected to said crank shaft, said cam member comprising a reset surface a fixed radius surface and a closing surface, during said manual closing operation of said circuit breaker said cam member moving in one direction to move said reset surface against said cam follower to effect a resetting operation of said circuit breaker and then to move said closing surface against said cam follower to thrust said cam follower to the closed position to move said movable contact arm to the closed position and said cam member then moving to move said fixed radius surface against said cam follower during which movement of said fixed radius surface against said cam follower said fixed radius surface serves to prop said cam follower such that movement of said cam member while said fixed radius surface is adjacent said cam follower will not affect the closed position of said movable contact arm.
 8. A circuit breaker according to claim 1, said circuit breaker comprising a linkage and latch means latching said linage in a reset position when said contacts are closed and said crank shaft is in said spring-discharged position, and said circuit breaker comprising interlock means automatically operable to prevent cooperative engagement between said pull member and said catch means when said linkage is in said reset position and said circuit breaker is in the spring-discharged contact-closed position.
 9. A circuit breaker according to claim 6, said cam means comprising a cam follower connected to said linkage and a cam member connected to said crank shaft, upon operation of said manually operable member from said initial position to said operating position said pull member operating when said contact arm is in the open position and said linkage is in the collapsed position to cooperate with said catch means to rotate said crank shaft from said spring-discharged position to said spring-charged operating position during which movement of said cam member operates said cam follower to effect a resetting operation of said linkage and a relatching of said reset linkage prior to movement of said crank shaft overcenter and during which furthEr movement of said crank shaft said crank shaft moves overcenter to said spring-charged operating position whereupon said closing spring means takes over to move said crank shaft in said operating direction from said spring-charged operating position to said spring-discharged position during which movement of said cam member operates through said cam follower and said reset latched linkage to move said movable contact arm to the closed position, and interlock means operating automatically to prevent cooperative engagement between said pull member and said catch means when said contact arm is in said closed position.
 10. A circuit breaker according to claim 9, and said interlock means comprising a first interlock member connected to said pull member and a second interlock member connected to said linkage. 